Rodríguez A, Diez C, Ikeda S, Royo L J, Caamaño J N, Alonso-Montes C, Goyache F, Alvarez I, Facal N, Gomez Enrique
Genética y Reproducción, SERIDA, Gijón, Asturias, Spain.
Hum Reprod. 2006 Aug;21(8):2149-57. doi: 10.1093/humrep/del099. Epub 2006 Apr 10.
The conversion of retinol (ROH) to retinoic acid (RA) is crucial during development but has been not studied during blastocyst formation.
In vitro-produced bovine morulae were treated for 24 h with citral (which inhibits the synthesis of RA from ROH), citral + all trans retinoic acid (ATRA), ATRA or no additives. Citral interfered with blastocyst development, whereas exogenous RA had no effect. RA, however, reversed the effect of citral on development and stimulated cell proliferation. Neither citral nor RA changed the apoptotic index, but RA triggered an increase in the apoptotic frequency of the inner cell mass. Citral and RA reduced the necrotic index. Na/K-ATPase alpha1-subunit mRNA concentrations (analysed by real-time PCR) increased after hatching and showed dependence on retinoid activity, but no evidence was found of any retinoid effect on p53 expression. Nevertheless, the p53 mRNA concentration increased in response to proliferation in hatched blastocysts.
The preimplantation bovine embryo metabolizes endogenous ROH to RA, which participates in important cell processes. The true extent of the influence of RA is unknown, although the modulation of retinoid metabolism seems to be a means of increasing cell proliferation. This knowledge might be used to improve embryo quality and the efficiency of stem cell derivation.
视黄醇（ROH）向视黄酸（RA）的转化在发育过程中至关重要，但在囊胚形成过程中尚未得到研究。
将体外产生的牛桑椹胚用柠檬醛（抑制从ROH合成RA）、柠檬醛+全反式视黄酸（ATRA）、ATRA或不添加任何物质处理24小时。柠檬醛干扰囊胚发育，而外源性RA没有影响。然而，RA逆转了柠檬醛对发育的影响并刺激细胞增殖。柠檬醛和RA均未改变凋亡指数，但RA引发了内细胞团凋亡频率的增加。柠檬醛和RA降低了坏死指数。孵化后，通过实时PCR分析的钠钾ATP酶α1亚基mRNA浓度增加，并显示出对视黄酸活性的依赖性，但未发现视黄酸对p53表达有任何影响的证据。尽管如此，在孵化的囊胚中，p53 mRNA浓度因增殖而增加。
植入前的牛胚胎将内源性ROH代谢为RA，RA参与重要的细胞过程。尽管视黄酸代谢的调节似乎是增加细胞增殖的一种方式，但RA影响的真实程度尚不清楚。这一知识可能用于提高胚胎质量和干细胞衍生效率。
